Question: When did Maximilian I, Holy Roman Emperor, marry Bianca Maria Sforza?
Paraphrase: On what date did Maximilian I, Holy Roman Emperor, marry Bianca Maria Sforza?
SPARQL (Wikidata): SELECT ?value WHERE { wd:Q150726 p:P26 ?s . ?s ps:P26 wd:Q161136 . ?s pq:P580 ?value}